Respirator with integral rib for clamping filter element and sealing breathing opening



7 2 5 8% T 2 I G m N E P O G W 9 m1 L E p m wm H G1- n m p L MA m 1 D1 NF g RESPIRATOR WITH INTEGRAL RIB FOR CLA ELEMENT INVENTOR. D. Hill BYBOW SW,

John

A TTOPNE Y5 United States Patent RESPIRATOR WITH INTEGRAL RIB FORCLANIP- ING FILTER ELEMENT AND SEALING BREATH- ING OPENING John D. Hill,Rocky River, Ohio, assignor to Flexo Prodgiltis, Incorporated,Cleveland, Ohio, a corporation of Application April 30, 1957, Serial No.656,031 Claims. (Cl. 128-l46) This invention relates to a mask typerespirator of the type in which an air filtering element is marginallyclamped between interfitted frame members, one frame member being formedand adapted to be disposed against and conform to the face of thewearer. More particularly, the invention is concerned with such arespirator in which the frame members are of resilient plastic materialformed as by injection molding.

One of the principal objectives of the invention is to provideimprovements in the type of mask disclosed in my prior United StatesPatent No. 2,578,007 issued December 11, 1951, to the end that theplastic frames maintain a more effective seal and a better grip on thoseside portions of the filter element that are disposed along the cheeksof the wearer. Reference is also made to my copending application forpatent on Respirator Mask, Serial No. 427,106, filed May 3, 1954,describing and claiming common subject matter.

Another object is to provide a respirator of molded plastic frames inwhich the labial or check portions of one of the interfitted frames arereinforced by upstanding rib elements that not only resist objectionablebending and distortion of the frame in use but are also effective ingripping the respirator filter element edges and sealing the filterelement along the side frame elements of the frame members. Theinvention contemplates the provision of specialized filter holding andsealing and frame reinforcing formations on the labial portions of atleast one of the respirator parts. More specifically it is contemplatedto provide a number of teeth or protuberances in combination with anintegral tooth linking rib on one of the respirator parts, the teeth andthe rib being so positioned as to bite into or become embedded in themargin of the filter element. In the best version presently known, aseries of spaced protuberances or teeth are formed on the confrontingsurfaces of each of the respirator parts, the teeth of the underlyingseries being linked by an integral upstanding rib which seals the spacesbetween the teeth.

The filter holding teeth are arranged in rows extending in linessubstantially paralleling the margins of the frame members of therespirator that define the breathing opening. The row or rows of teethon the inner or underlying frame member are connected by the integralrib and are closer to the breathing opening than are the associated rowor rows of teeth on the outer or overlying confronting frame member sothat the rib connected teeth of the inner frame member engage the filterelement relatively close to the breathing opening, the teeth on theouter frame member engaging the filter element at a greater distancefrom the breathing opening and holding the filter against the sealingrib.

Other objects and advantages relate to certain structural details andcombinations of parts as set forth in the following detailed descriptionof a preferred embodiment of the invention which represents the bestknown mode of practicing its principles. This description is 2,845,927Patented Aug. 5, 1958 made in connection with the accompanying drawingsforming a part of the specification.

In the drawing:

Fig. 1 is an expanded view, with parts broken away and removed, showingthe principal components of the respirator in perspective;

Fig. 2 is a front view of the respirator, partly in section and withparts broken away and removed, this view showing the several componentsassembled together; and

Fig. 3 is a sectional detail taken in the plane represented by the line3-3 of Fig. 2 and enlarged with respect to that figure.

The respirator comprises inner and outer frame members A and B,respectively, an attaching head band C of elastic material such asrubber and a porous filter element D. The frame members are formed ofresilient shape-retaining material, being of generally thin section andyieldable so as to conform to varying facial contours of differentpersons while being capable of resuming their natural molded shapesafter each use. For example, the frame members shown are formed as byinjection molding of a thermoplastic material such as polyethylenewhich, in addition to its desirable characteristics of resilience anddurability, is neutral and therefore will not irritate the skin of thewearer.

The inner frame member A is generally triangular in shape and is cuppedto receive the nose and mouth of the wearer. it comprises a horizontalportion 1 which extends across and rests against the chin of the wearer.Side or check portions 2 and 3 are oblique or at an acute angle tobottom portion 1 and are curved rearwardly away from the bottom portionso as to overlie the checks of the wearer. The side portions are taperedand generally of greater width than the chin portion 1 and areintegrally joined together by top portion 7 which overlies the nose ofthe wearer. The bottom and side portions of the inner member A thusdefine an inverted heart or V shaped breathing opening 5 across which isdisposed filter element D. The inner frame member A includes a frontportion 6 curved downwardly from the top or bridge portion 7 anddisposed across the top of the breathing opening. The front portion 6 isintegrally joined to the rearwardly extending top 7 which, with the sideportions 2 and 3, provides an enclosing bridge for the wearers nose. Therear edges of the oblique sides 2 and 3 are formed with outwardlycurving integral tab portions 4 that fit in the angles between thewearers nose and checks. These tabs are generally thinner than the sidesand other parts of the frame member A, thus being more flexible toobtain the desired yielding and conforming comfortable fit. The filterelement D is a mat or pad of any suitable porous material in the form ofwoven gauze of cotton or other fiber, or felted mat of fibrous glass,natural or synthetic fiber or combination thereof, or it may be terrycloth, natural or artificial sponge, foam latex or a poly urethane foam.

The outer frame member B is complementally shaped with respect to theinner frame member A but is of less area or extent than the latter.Breathing opening 8 in the outer frame member B corresponds in shape tothe breathing opening 5 of the inner frame member.

The outer frame member includes chin, oblique side and top frontportions 11, 12, 13 and 16 corresponding respectively to the portions 1,2, 3 and 6 of the inner frame member A. These corresponding portions ofthe inner and outer frame members are complementally shaped and adjacentthe breathing openings 5, 8 have confronting faces which clamp betweenthem marginal portions 14 of the filter element D around the entireperiphery of the latter.

Along the upper edge of the top front portion 16 of the outer framemember is formed an integral angularly disposed and rearwardly extendingflange 17 which is arranged to overlie the nasal bridge or arch 7 of theinner frame member to locate and hold the two frame members inpredetermined relative positions and to support the outer frame memberon the inner.

The front portion 16 and the nasal bridge portion 17 of the outer member8 cooperatively define a relatively large pocket 15 that locatinglyreceives a complemental part of the inner member comprising the frontand nasal bridge portions 6 and 7 respectively.

At each side of the mask respirator the side portions 12 and 13 of theouter frame member are formed adjacent their rearmost ends withvertically elongated openings 18 which receive laterally projectingextensions or horns 19 formed integrally on the adjacent side portions 2and 3 of the inner frame member A. The rearmost side edges of thegenerally triangular filter element D are notched out as indicated at 23in the provision of locating recesses that receive the horns 19.

The headband C is in the form of an adjustable length flexible strap ortape preferably comprising elastic strip rubber to retain the respiratorframe snugly against the wearers face. in assembling the respirator theends of a suitable adjustable length elastic rubber band or tape C arethreaded through openings 20 in rearwardly extending integral tabs 24 ofthe inner part side portions 2 and 3. The rubber band ends have integralenlargements or knobs 22 which are shaped and sized to permit insertionthrough the slots 20 in assembly but resist withdrawal in normal use.

Augmentation of the grip of the frame members on the filter element D isobtained by a combination of integral ribs and square shaped teethextending along the confronting surfaces of the members adjacent theopenings 5, 8. A series of teeth 31 are formed on the outwardly directedface of the chin portion 1 of the frame member A. These teeth arearranged in a row paralleling and relatively close to the edge of theinner member defining the breathing opening 5. Similar teeth 32 arearranged in lines along the oblique side portions 2 and 3 of the innermember parallel to and relatively close to the edges of the sideportions which define the breathing opening. The teeth 31 and 32 projecttoward the confronting internal surfaces of the corresponding chin andside portions of the outer frame part B and the latter is formed withinwardly directed teeth (not shown) on the chin portion 11 and inwardlydirected teeth 34 on the oblique side portions 12 and 13. The rows ofteeth 34 are spaced farther from the breathing opening than are thecorresponding or companion teeth 32 of the inner member so that the rowsof teeth on the two frame members being laterally offset from andparallel to one another, form a wave comprising bends 28, 29 (Fig. 3) inthe filter element D parallel to its edges. The clamping teeth arediscontinuous across the junctures between the bottom chin portions orelements of the frames and the adjacent oblique side portions orelements and also across the junctions at the top nasal bridges betweensuch side portions or elements.

An integral endless bead 35 is formed on the outer member B and extendsunbroken about the entire breathing opening 8. This bead projectsinwardly or into the plane of the opening and is engaged against theoutward surface of the filter element.

The side portions or elements 2 and 3 of the inner frame member A,integrally connected at their lower ends to the opposite ends of thebottom element 1 and inclined toward one another, curve rearwardly andprogressively increase in width toward the top of the respirator wherethey are integrally joined together to form the nasal bridge 7 and thetop frontal portion 6. They are formed with integral upstanding ribs 36adjacent but spaced from their forward frame edges which defines thebreathing opening 5. Each of these ribs is normal to outwardly directedsurface portion 37 of the inner frame member A on which is formed andwhich confronts a companion inwardly directed surface portion 38 of theouter frame 13. As shown to advantage in Figure 3 the upstanding rib 36on the side element 2 of the inner frame member A lies between the lineof the teeth 34 and the beaded edge 35 on the side element 12 of theouter member B when the respirator is assembled. Similarly in theassembled device, the rib 36 on the side element 3 of the inner framemember A lies between the line of the teeth and the beaded edge 35 ofthe confronting companion portion of the outer frame side element 13.

The ribs 36 as well as the teeth 32 of the inner frame are thus offsetlaterally toward the registered breathing openings of the frame memberswith respect to the lines of the inwardly directed teeth orprotuberances 34 of the outer frame. This arrangement has the effect ofplacing the bends 28 of the clamped filter element C about or over thecrests or tops of the upstanding ribs 36. The tooth protuberances 32,being wholly on that side of each of the respective ribs 36 which isdirected forwardly toward the breathing opening, leave the other orrearwardly directed surfaces of the ribs smooth and unobstructed foreffecting sealing engagement with the inside surface of the filter Calong lines spaced from the breathing opening. The sealing lines of therib edges against the filter C are, however, spaced toward the breathingopening from the lines of the outside teeth or protuberances 34 whichthus hold the filter against the sealing rib crests. Thus effectiveseals are provided between the inside of the filter C and the sideportions of the inner frame member A preventing ingress of air betweenthe filter and the frame member when the respirator is in use.

As shown in Figure 1 the sealing ribs 36 integrally connect theindividual biting teeth 32 which extend along the major portions of eachof the inner frame side elements 2 and 3. The sealing ribs 36 as well asthe teeth are discontinuous across the top frontal portion 6 of theinner frame and across the lower portions of the side elements 2 and 3since at such regions the relatively wide areas of contact between thefilter element and the outside surface of the inner frame member areeffective to clamp the filter and maintain adequate seals. The teeth 31across the chin element 1 of the inner frame member may be supplementedby an integrally connected sealing and reinforcing rib (not shown)disposed wholly below such teeth so that the teeth 31 intervene betweenthe sealing rib and the frame edge definitive of the breathing opening5, all similarly to the combination of the ribs 36 and the filter bitingand clamping teeth 32 used along the major portions of the inner sideframe elements 2, 3. It is understood, of course, that the bottomelement 11 of the outer frame B has a series of teeth integrally formedon and projecting from its inside surface toward the confrontingoutwardly directed surface of the inner frame element 1. The cooperatingteeth of the bottom elements of the frames are related to one anotherand to the breathing opening edges of the frame elements in the same waythe teeth and the frame elements in Fig. 3 are related.

In addition to their function as a scaling factor between the innerframe member and the filter C, the ribs 36 reinforce those portions ofthe side frame elements 2, 3 adjacent the breathing opening. Thisreinforcement prevents objectionable bending of those portions of theinner frame side elements which border the breathing opening when therespirator is stressed in use by the tension in the head band C.

To change or replace the filter D while the respirator is being worn,the user draws outwardly on one or both of the side portions 12 and 13of the outer frame member adjacent the horn receiving openings 18 torelease the snap fit interlock of the horns 19. The outer frame member Bis thus released from the inner frame member A, allowing the latter toremain in position over the wearers nose and mouth. With the framemembers thus separated the filter element D is released from clampedposition between the confronting faces of the frame members, permittingit to be removed or withdrawn from the breathing opening in the front ofthe mask. With the outer frame member still withdrawn at new orreplacement filter is then disposed across the breathing opening 5 ofthe inner frame member and the outer frame member is returned toclamping position. The holding horns 19 are locatingly received in thenotches 23 of the filter element D. The frames may also be separated byrelatively springing apart the side portions of the inner and outerframe member to Withdraw them from off the extensions or horns 19, thusreleasing the frame members from their clamping engagement on the filterelement.

In accordance with the provisions of the patent statutes, the principlesof the present invention may be utilized in various ways, numerousmodifications and alterations being contemplated, substitution of partsand changes in construction being resorted to as desired, it beingunderstood that the embodiment shown in the drawing and illustratedabove is given merely for the purposes of explanation and illustrationwithout intending to limit the scope of the claims to the specificdetails disclosed.

What I claim and desire to secure by Letters Patent of the United Statesis:

1. A mask type respirator device receivable over the nose and mouth of awearer, said respirator comprising separable inner and outer framemembers of resilient plastic material nested together, the frame memberseach being formed with a front breathing opening registered with thebreathing opening of the other, each frame member having a bottomelement for disposition across the chin of the wearer and side elementsintegrally connected at their lower ends to the spaced ends of thebottom chin element, the side elements of each frame member beinginclined toward one another and integrally connected together at the topof the device, a filter of deformable material disposed and peripherallyclamped between the frame members and extending across the registeredbreathing openings, a band connected to one of the members forencircling the head of the wearer and holding the device in place overthe wearers nose and mouth, the elements of the inner and outer membershaving respectively outwardly and inwardly directed surfaces borderingthe breathing opening, such outwardly directed surfaces of the innermember being disposed in confronting relation to the correspondinginwardly directed surfaces of the outer member so as to be disposed onopposite sides of a clamped filter, the members each being formed withintegral spaced protuberances on the confronting surfaces to bite intothe filter, the protuberances on one member being laterally offsetrelative to those on the other member whereby to effect a bending of thefilter periphery, and at least one of the elements of the inner memberhaving an integral upstanding narrow rib paralleling that edge of suchinner element which defines the breathing opening therein, said ribextending between and integrally connecting a plurality of theprotuberances of such inner element whereby the rib constitutes a sealpreventing leakage of air between the inner member and the filteradjacent the points of engagement between the filter and thoseprotuberances connected by the rib.

2. A mask type respirator device receivable over the nose and mouth of awearer, said respirator comprising separable inner and outer framemembers of resilient plastic material nested together, the frame memberseach being formed with a front breathing opening registered with thebreathing opening of the other, each frame member having a bottomelement for disposition across the chin of the wearer and side elementsintegrally connected at their lower ends to the spaced ends of thebottom chin element, the side elements of each frame member beinginclined toward one another and integrally connected together at the topof the device, a filter of deformable material disposed and peripherallyclamped between the frame members and extending across the registeredbreathing openings, a band connected to one of the members forencircling the head of the wearer and holding the device in place overthe wearers nose and mouth, the elements of the inner and outer membershaving respectively outwardly and inwardly directed surfaces borderingthe breathing opening, such outwardly directed surfaces of the innermember being disposed in confronting relation to the correspondinginwardly directed surfaces of the outer member so as to be disposed onopposite sides of a clamped filter, the members each being formed withintegral spaced protuberances on the confronting surfaces to bite intothe filter, the protuberances on the inner member including along atleast one of its elements a series along a line closer to the registeredbreathing openings than the corresponding protuberances on theconfronting surface of the outer member whereby a marginal edge portionof the filter is bent inwardly by such corresponding protuberances ofthe outer member along and about the line of the series on the innermember, the inner member being formed with an integral upstanding ribparalleling the series of protuberances, and said rib being engagedthroughout its length by the inside surface of the filter in theprovision of a seal between the inner member and the filter along a linespaced outwardly from the surface of the inner member on which theseries of protuberances are formed.

3. A mask type respirator device receivable over the nose and mouth of awearer, said respirator comprising separable inner and outer framemembers of resilient plastic material nested together, the frame memberseach being formed with a front breathing opening of the other, eachframe member having a bottom element for disposition across the chin ofthe wearer and side elements integrally connected at their lower ends tothe spaced ends of the bottom chin element, the side elements of eachframe member being inclined toward one another and integrally connectedtogether at the top of the device, a filter of deformable materialdisposed and peripherally clamped between the frame members andextending across the registered breathing openings, a band connected toone of the members for encircling the head of the wearer and holding thedevice in place over the wearers nose and mouth, the elements of theinner and outer members having respectively outwardly and inwardlydirected surfaces bordering the breathing opening, such outwardlydirected surfaces of the inner member being disposed in confrontingrelation to the corresponding inwardly directed surfaces of the outermember so as to be disposed on opposite sides of a clamped filter, themembers each being formed with integral spaced protuberances on theconfronting surfaces to bite into the filter, the protuberances on theinner member including along at least one of its elements a series alonga line closer to the registered breathing openings than thecorresponding protuberances on the confronting surface of the outermember whereby a marginal edge portion of the filter is bent inwardly bysuch corresponding protuberances of the outer member along and about theline of the series on the inner memher, the inner member being formedwith an upstanding rib connecting and integral with the protuberances ofsaid series, and said rib being engaged throughout its length by theinside surface of the filter in the provision of a seal between theinner member and the filter along a line spaced outwardly from thesurface of the inner member on which the series of protuberances areformed.

4. A mask type respirator device receivable over the nose and mouth of awearer, said respirator comprising separable inner and outer framemembers of resilient plastic material nested together, the frame memberseach being formed with a front breathing opening of the other, eachframe member having a bottom element for disposition across the chin ofthe wearer and side elements integrally connected at their lower ends tothe spaced ends of the bottom chin element, the side elements of eachframe member being inclined toward one another and integrally connectedtogether at the top of the device, a filter of deformable materialdisposed and peripherally clamped between the frame members andextending across the registered breathing openings, a band connected toone of the members for encircling the head of the wearer and holding thedevice in place over the wearers nose and mouth, the elements of theinner and outer members having respectively outwardly and inwardlydirected surfaces bordering the breathing opening, such outwardlydirected surfaces of the inner member being disposed in confrontingrelation to the cor responding inwardly directed surfaces of the outermember so as to be disposed on opposite sides of a clamped filter, themembers each being formed with integral spaced protuberances on theconfronting surfaces to bite into the filter, the protuberances on theinner member including along at least one of its elements a series alonga line closer to the registered breathing openings than thecorresponding protuberances on the confronting surface of the outermember whereby a marginal edge portion of the filter is bent inwardly bysuch corresponding protuberances of the outer member along and about theline of the series on the inner member, the inner member being formedwith an upstanding rib connecting and integral with the protuberances ofsaid series, the protuberances of said series being located wholly onthat side of the rib toward the breathing opening, the other side of therib presenting a smooth and unbroken surface for engagement by thefilter, and said rib being engaged throughout its length by the insidesurface of the filter in the provision of a seal between the innermember and the filter along a line spaced outwardly from the surface ofthe inner member on which the series of protuberances are formed.

5. A mask type respirator device receivable over the nose and mouth of awearer, said respirator comprising separable inner and outer framemembers of resilient plastic material nested together, the frame memberseach being formed with a front breathing opening of the other, eachframe member having a bottom element for disposition across the chin ofthe wearer and side elements integrally connected at their lower ends tothe spaced ends of the bottom chin element, the side elements of eachframe member being inclined toward one another and integrally connectedtogether at the top of the device, a filter of deformable materialdisposed and peripherally clamped between the frame members andextending across the registered breathing openings, a band connected toone of the members for encircling the head of the wearer and holding thedevice in place over the wearers nose and mouth, the elements of theinner and outer members having respectively outwardly and inwardlydirected surfaces bordering the breathing opening, such outwardlydirected surfaces of the inner member being disposed in confrontingrelation to the corresponding inwardly directed surfaces of the outermember so as to be disposed on opposite sides of a clamped filter,

P the members each being formed with integral spaced pro tuberances onthe confronting surfaces to bite into the filter, the protuberances onthe inner member including along at least one of its elements a seriesalong a line closed to the registered breathing openings than thecorresponding protuberanees on the confronting surface of the outermember whereby a marginal edge portion of the filter is bent inwardly bysuch corresponding protuberances of the outer member along and about theline of the series on the inner member, the inner member being formedwith an upstanding ri'o connecting and integral with the protuberancesof said series, the protuberances of said series being located wholly onthat side of the rib toward the breathing opening, the other side of therib presenting a smooth and unbroken surface for engagement by thefilter, and the rib being disposed in a. plane generally normal to saidsurface of the inner member, the line of the series of protuberances onthe inner member being on one side of the plane and said outer membercorresponding protuberances being disposed to engage the outside surfaceof the filter along a line on the other side of such plane whereby theclamped filter is deformed to S shape in section along its marginsdisposed between the side elements of the frames and the edge of theupstanding sealing rib is engaged against a concave portion of theinside surface of the filter in the establishment of a line contactseal.

Hill Dec. 11, 1951 Lewis June 26, 1956 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 2,845,927 August 5, 1958 John D.Hill s in the printed specification ified that error appear d that thesaid Letters patent requiring correction an rected below.

It is hereby cert of the above numbered Patent should read as cor dcloser Column 8, line 19, for "closed rea Signed and sealed this 22ndday of March 1960.

(SEAL) Atiest:

ROBERT C. WATSON KA L H. AXLINE Attesting Officer Comnissioner ofPatents

